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parameterize | To supply the required value for an attribute of a device at | ||
PDM | power distribution module. A module that distributes either AC or DC field power to | ||
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| a cluster of I/O modules directly to its right on the island bus. A PDM delivers field |
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| power to the input modules and the output modules. It is important that all the I/O |
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| clustered directly to the right of a PDM be in the same voltage |
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| 24 VDC, 115 VAC, or 230 VAC. |
PDO | process data object. In | ||
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| broadcast messages or sent from a producer device to a consumer device. The |
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| transmit PDO from the producer device has a specific identifier that corresponds to |
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| the receive PDO of the consumer devices. |
PE | protective earth. A return line across the bus for fault currents generated at a sensor | ||
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| or actuator device in the control system. |
In | |||
communications | relationship. Messages are exchanged between entities of comparable or | ||
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| equivalent levels of functionality, without having to go through a third party (like a |
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| master device). |
PLC | programmable logic controller. The PLC is the brain of an industrial manufacturing | ||
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| process. It automates a process as opposed to relay control systems. PLCs are |
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| computers suited to survive the harsh conditions of the industrial environment. |
preferred module | An I/O module that functions as an | ||
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| island but is not in the same form factor as a standard Advantys STB I/O module and |
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| therefore does not fit in an I/O base. A preferred device connects to the island bus |
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| via an STB XBE 1000 EOS module and a length of STB XCA 100x bus extension |
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| cable. It can be extended to another preferred module or back into a standard island |
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| segment. If it is the last device on the island, it must be terminated with a 120 Ω |
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| terminator. |
premium | An Advantys STB network interface module designed at a relatively high cost to | ||
network | support high module densities, high transport data capacity (e.g., for web servers), | ||
interface | and more diagnostics on the island bus. | ||
prioritization | An optional feature on a standard NIM that allows you to selectively identify digital | ||
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| input modules to be scanned more frequently during a the NIM’s logic scan. |
890USE19600 April 2004 | 63 |